Studies On MTB Specific Recombination Antigen In TB Serology Diagnosis

[objective]To set up a standard detection system of mycobacterium tuberculosis (MTB) specific antigen-recombinated Mtb8.4, 38KD, MPT64 and MPT63 protein by enzyme-linked immunosorbent assay(ELISA). To try to raise the diagnostic level of TB in the clinical laboratory with the methods of four species antigen combination.[methods]The square matrix method and Receiver Operating Characteristic (ROC) is used to determine the best concentration of antigen-Mtb8.4 38KD MPT64 and MPT63 coated and the best concentration of enzyme diluted. Using the standard ELISA system that has been set up detects the clinical samples collected. Receiver Operating Characteristic method is used to determine the cut-off,the sensibility and the specificity of four antigen respectively in ELISA. To approach a establishment of standard ELISA system. At the same time, the clinical samples were detected by acid-fast staining and MTB antibody method. To compare the sensibility and the specificity among methods.[results] 1. The best concentration of antigen coated were 1: 32000,1: 64000,1: 64000 and 1: 128000 for MTB specific antigen-recombinated Mtb8.4 38KD, MPT64 and MPT63 proteins in ELISA respectively, and the best concentration of enzyme diluted were 1: 1000, 1: 1000, 1: 1000 and 1: 1000 respectively,which gain the sensibility 47.60% ,59.60%,68.00% and 70.41%, and the specificity 93%,92.30%, 92.30% and 87.25% respectively.ELISA system might attain higher sensibility and specificity, when four species antigen was combined. 2.The sensibility of three methods—acid-fast staining,MTB antibody method and four species antigen combination method were 42.2% 51.9% and 82.4% respectively, and the specificity of MTB antibody method and four species antigen combination method were 81.8%和88.3% respectively.3. Among three methods have deviation.[conclusions]The critical factors in ELISA are that the square matrix method determine the concentration of protein coated and the concentration of enzyme diluted,and ROC determine cut-off. Association MTB specific antigen-recombinated Mtb8.4 38KD MPT64 and MPT63 proteins make the sensibility and the specificity higher in TB serology diagnosis.